Example usage for com.google.common.hash Hashing combineOrdered

Introduction

In this page you can find the example usage for com.google.common.hash Hashing combineOrdered.

Prototype

public static HashCode combineOrdered(Iterable<HashCode> hashCodes) 

Source Link

Document

Returns a hash code, having the same bit length as each of the input hash codes, that combines the information of these hash codes in an ordered fashion.

Usage

From source file:io.druid.server.router.RendezvousHasher.java

public <KeyType> String chooseNode(Set<String> nodeIds, byte[] key) {
    if (nodeIds.isEmpty()) {
        return null;
    }//from  w  w w.j  a v a 2 s.c  o m

    final HashCode keyHash = HASH_FN.hashBytes(key);
    long maxHash = Long.MIN_VALUE;
    String maxNode = null;

    for (String nodeId : nodeIds) {
        HashCode nodeHash = HASH_FN.hashString(nodeId, Charsets.UTF_8);
        List<HashCode> hashes = Lists.newArrayList(nodeHash, keyHash);
        long combinedHash = Hashing.combineOrdered(hashes).asLong();
        if (maxNode == null) {
            maxHash = combinedHash;
            maxNode = nodeId;
        } else if (combinedHash > maxHash) {
            maxHash = combinedHash;
            maxNode = nodeId;
        }
    }

    return maxNode;
}

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From source file:org.apache.druid.server.router.RendezvousHasher.java

public <KeyType> String chooseNode(Set<String> nodeIds, byte[] key) {
    if (nodeIds.isEmpty()) {
        return null;
    }/*  w  w w . j a v  a2 s . c o  m*/

    final HashCode keyHash = HASH_FN.hashBytes(key);
    long maxHash = Long.MIN_VALUE;
    String maxNode = null;

    for (String nodeId : nodeIds) {
        HashCode nodeHash = HASH_FN.hashString(nodeId, StandardCharsets.UTF_8);
        List<HashCode> hashes = Lists.newArrayList(nodeHash, keyHash);
        long combinedHash = Hashing.combineOrdered(hashes).asLong();
        if (maxNode == null) {
            maxHash = combinedHash;
            maxNode = nodeId;
        } else if (combinedHash > maxHash) {
            maxHash = combinedHash;
            maxNode = nodeId;
        }
    }

    return maxNode;
}

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From source file:com.facebook.buck.android.UberRDotJava.java

public Optional<DexWithClasses> getRDotJavaDexWithClasses() {
    Preconditions.checkState(rDotJavaNeedsDexing,
            "Error trying to get R.java dex file: R.java is not supposed to be dexed.");

    final Optional<Integer> linearAllocSizeEstimate = buildOutputInitializer
            .getBuildOutput().rDotJavaDexLinearAllocEstimate;
    if (!linearAllocSizeEstimate.isPresent()) {
        return Optional.absent();
    }//from  w  w w.  j a  v a2  s  .c om

    return Optional.<DexWithClasses>of(new DexWithClasses() {
        @Override
        public Path getPathToDexFile() {
            return getPathToRDotJavaDex();
        }

        @Override
        public ImmutableSet<String> getClassNames() {
            throw new RuntimeException("Since R.java is unconditionally packed in the primary dex, no"
                    + "one should call this method.");
        }

        @Override
        public Sha1HashCode getClassesHash() {
            return Sha1HashCode.fromHashCode(Hashing.combineOrdered(getClassNamesToHashes().values()));
        }

        @Override
        public int getSizeEstimate() {
            return linearAllocSizeEstimate.get();
        }
    });
}

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